Over 650 Million omnidirectional 60 watt incandescent light bulbs were sold in the United States in 2008. Many light fixtures require omnidirectional light, i.e. light which emanates in all directions; upward, laterally, and downward to simultaneously illuminate work tasks, writing, and to decoratively illuminate a wall or ceiling architectural feature as required for interior design illumination. Incandescent and halogen lights are heater filaments which produce only 12-15 lumens/Watt. There is a need for high luminous efficacy solid-state lighting sources which can match the incandescent light source in appearance both in terms of color quality, and in distribution of the light.
Currently, 2009 90CRI warm white LED light is commercially available at 100 lumens/Watt, with advancements accelerating the availability of 150 lumen/Watt warm white light sources very soon at larger single chip sizes up to 25 mm^2 capable of producing greater than 4000 lumens. Previous generation solutions to the production of semi-omnidirectional LED light have failed to achieve the efficiency and lifetime required to solidify a strong buy position for those interested in energy-efficient lighting technology.